/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2007 CaH4e3
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * FDS Conversions
 *
 * Super Mario Bros 2 J alt version
 * as well as "Voleyball" FDS conversion, bank layot is similar but no bankswitching and CHR ROM present
 *
 * mapper seems wrong researched by me ;( it should be mapper 43 modification
 */

#include "mapinc.h"

static uint8 prg, IRQa;
static uint16 IRQCount;

static SFORMAT StateRegs[] =
{
	{ &prg, 1, "PRG" },
	{ &IRQa, 1, "IRQA" },
	{ &IRQCount, 2, "IRQC" },
	{ 0 }
};

static void Sync(void) {
	setprg4r(1, 0x5000, 1);
	setprg8r(1, 0x6000, 1);
	setprg32(0x8000, prg);
	setchr8(0);
}

static DECLFW(UNLSMB2JWrite) {
	if (A == 0x4022) {
		prg = V & 1;
		Sync();
	}
	if (A == 0x4122) {
		IRQa = V;
		IRQCount = 0;
		X6502_IRQEnd(FCEU_IQEXT);
	}
}

static void UNLSMB2JPower(void) {
	prg = ~0;
	Sync();
	SetReadHandler(0x5000, 0x7FFF, CartBR);
	SetReadHandler(0x8000, 0xFFFF, CartBR);
	SetWriteHandler(0x4020, 0xffff, UNLSMB2JWrite);
}

static void UNLSMB2JReset(void) {
	prg = ~0;
	Sync();
}

static void FP_FASTAPASS(1) UNLSMB2JIRQHook(int a) {
	if (IRQa) {
		IRQCount += a * 3;
		if ((IRQCount >> 12) == IRQa)
			X6502_IRQBegin(FCEU_IQEXT);
	}
}

static void StateRestore(int version) {
	Sync();
}

void UNLSMB2J_Init(CartInfo *info) {
	info->Reset = UNLSMB2JReset;
	info->Power = UNLSMB2JPower;
	MapIRQHook = UNLSMB2JIRQHook;
	GameStateRestore = StateRestore;
	AddExState(&StateRegs, ~0, 0, 0);
}
